Someone with poor nonverbal skills, however, may give off an impression of low self-esteem and a lack of interest, she says. “Is this 100% fair? Not necessarily. But it is how humans are programmed.”

When dealing with the business world, it’s especially important that you’re aware of your body language. Your nonverbal cues and gestures can make or break relationships, and may have a significant impact on your success.

Here are 11 common body language mistakes employees make:

Poor posture. How we feel affects how we stand. In order to be perceived as confident, you must stand tall, with your neck elongated, ears and shoulders aligned, chest slightly protruding, and legs slightly apart, distributing weight evenly, Reiman says. “This does several things. It changes the chemicals in our brain to make us feel stronger and more confident, and it gives the outward appearance of credibility, strength, and vitality.”

People often slump their shoulders either due to bad backs, fatigue, lack of confidence, or general disregard. “This will give others the impression of insecurity, laziness, and a general sense of unhappiness.”

Not being in sync. When we like someone, we naturally match and mirror their voice, tone, tempo, body posture, and movements, says Patti Wood, a body language expert and author of “SNAP: Making the Most of First Impressions Body Language and Charisma.” “If you were to watch the conversation on a video, it might look like you’re dancing with the other person. If you don’t ‘dance’ with your teammates it can make you look you're not interested in what they are saying, you are not a good team player, or, in the extreme cases, that you are lying.”

Fidgeting and “big” hand movements. In business, small gestures tend to demonstrate the biggest points. “It is rare to see the alpha of the group wildly flailing about,” Reiman says. “Powerful business people tend to use smaller, more subtle hand gestures to demonstrate their point with authority.”

However, so many people in the workplace today make big hand gestures or fidget with their hands, phone, or hair. “This demonstrates weakness and a lack of confidence.”

Giving no physical feedback or facial expression. A big mistake a lot of employees make that can be detrimental to their success: They show no empathy or interest in what their colleagues are saying. “We often express interest through raised eyebrows, smiles, head nods, vocal utterances (like ‘uh-huh’), and leaning forward,” Wood says. “If you don’t give feedback physically, people think you don’t care, that you’re stuck up, and host of other negative attributes.”

No eye contact. "Cultural respective eye contact is one of the main components of nonverbal communication," Reiman explains. The ability to gaze at another while speaking denotes authority, confidence, and presence. “Studies suggest that holding eye contact while speaking has an enormous impact on your ability to persuade. Lack of eye contact often implies deception,” she says. When breaking eye contact, it is better to break off to the left or to the right, as looking down suggests insecurity.

Bad handshake. Ideally, your handshake should be firm, but not overbearing. “The secret to a great handshake is palm-to-palm contact,” Wood says. You want to slide your hand down into the web of theirs, and make palm-to-palm contact. Lock thumbs, and apply an equal amount of pressure.

Mismatching verbal and nonverbal messages. Making facial expressions that appear to show the opposite emotional reaction to what you are saying is another common mistake, Wood says. For example: You say, “that sounds great” in a monotone voice, while you cross your arms and roll your eyes. “I believe this is the worst mistake any communicator can make,” she says. “Some people do it as a passive aggressive way of getting their message across.”

Failing to smile. “The smile is accompanied by increased activity in the left pre-frontal cortex — the seat of positive emotions,” Reiman says. Smiling demonstrates confidence, openness, warmth, and energy. It also sets off the mirror neurons in your listener instructing them to smile back, she says. Without the smile, an individual is often seen as grim or aloof.

“Of course, worse than the ‘non-smiler’ is the ‘permagrinner,’ who smiles too often and is perceived as insincere and misleading,” Reiman adds.

Eye rolling. Eye rolling is a sign of contempt, frustration, exasperation, and aggression, Reiman says. "While for some it's a habit, it is a completely conscious act that can be avoided with self-awareness." Eye rolling signals to your listener that you don’t appreciate or respect them or what they are saying. "This is such a strong signal that researchers have proven that rolling your eyes after a spouse has spoken is a strong predictor of divorce," she says.

Keeping a cell phone out. Employees sometimes place their cell phone between themselves and the person they’re speaking to. “It says, symbolically, that this object is more important than they are, and that the phone is what you’d prefer to interact with.”

Crossing their arms defensively. Look around in a meeting and you’ll likely notice a few colleagues crossing their arms. “You should always keep your hands in view when you are talking,” Wood explains. “When a listener can’t see your hands, they wonder what you are hiding.” To look honest and credible, show your hands.